Optical imaging apparatus for producing three-dimensional images of samples by optical projection tomography is known, see for example U.S. Pat. No. 5,680,484. The optical apparatus disclosed in this prior art patent takes a series of digital images of a sample from different angles. These images are fed into an algorithm which use a mathematical transform to reconstruct a three dimensional image. In U.S. Pat. No. 5,680,484 the specimen is held within a transparent tube which is supported at two points so as to be substantially horizontal, and the tube is rotated using a stepper motor and driving belt to allow different parts of the specimen to be imaged. Light refraction from the tube affects signal quality and use of the tube places a severe constraint on the maximum size of specimen which can be imaged. The apparatus disclosed in this prior art patent has several limitations which affect the potential uses of this imaging technique, in particular it is difficult to introduce the sample into the hollow cylindrical tube, and difficult to adjust the position of the sample.
It is an aim of the present invention to provide an apparatus and method which overcome at least some of the aforementioned problems.